To rationalize tensioning and locking work of an electric heating wire 3 between first and second electric electrode parts 311 and 321 and to improve certainty/reliability of the locking of the electric heating wire.

The first and the second electric electrode parts 311 and 321 are metal plates not harder than the electric heating wire 3, the end part of the electric heating wire 3 is made to pass through a cut gap of projecting cut and bent parts 312 and 322 provided therein respectively and the projecting cut and bent parts 312 and 322 are pushed back by a press, so that the end part of the energizing and heating wire 3 is locked to the first and the second electric electrode parts 311 and 321.